Before the wave of multicoloured graffiti lined the walls, there were reportedly Native American cave paintings inside.

Plans the clean the cave by blasting it with walnut shells, which will preserve the walls but clear the paint, are now underway. The process will cost around $40,000 says Sap.

The cave is closed and no date has been set for it to be open to the public again as yet. Anyone who does enter the closed-off area will be subject to a $400 fine, and anyone found painting the cave will be charged an amount in the thousands, as well as facing felony charges.